A lot of my new third graders have not consolidated their irregular plural nouns. The Common Core Standards address this in second grade: L.2.1. Form and use frequently occurring irregular plural nouns (e.g., feet, children, teeth, mice, fish) and I have made some worksheets to match this.
I have two worksheets containing the most commonly used irregular plural nouns. All the student has to do is write the noun (e.g. mice) and then write it in a sentence to demonstrate understanding and ability to use it (e.g. I saw two mice). If these sheets are too difficult, then view my post on Irregular Plural Noun Cards and download some more free visual resources for teaching.